Locking means for offset backhoe



Oct. 29, 1968 v A. H. LEESE I 3,407,945

LOCKING MEANS FOR OFFSET BACKHOE Filed Dec. 7, 1966 5 Sheets-Sheet lINVENTOR 4450?? fif 142s:

AE'MJ Oct. 29, 1968 A. H. LEESE LOCKING MEANS FOR OFFSET BACKHOE 5Sheets-Sheet 2 Filed Dec. 7, 1966 INVENTOR A1554? h. 1:21;: I erATTORNEY United States Patent x v 3,407,945 LOCKING MEANS FOR OFFSETBACKI IOE Albert Harold Leese, Basildon, England, assignor to Ford.Motor Company, Dearborn, Mich., a corporation of Delaware Filed Dec. 7,1966, Ser. No. 599,770

4 Claims, (Cl. 214-138) ABSTRACT OF THE DISCLOSURE A locking means forthe carriage of an adjustable offset backhoe of the type including atransverse frame having a pair of C-shaped slots and expansible blockswithin the slots for supporting the carriage and holding it againstmovement along the slots is actuated by tightening the bolts holding thecarriage against the frame. Preferably, a cam surface on each of theblocks laterally expands the blocks upon tightening the bolts so thatthe blocks tightly engage opposing side walls of the C-shaped slots.

This invention relates to offset backhoes.

Tractor-mounted adjustable offset backhoes often are provided with aframe extending transversely of the rear of the tractor and forming atrack along which a carriage supporting thebackhoe boom may be moved toposition the backhoe to either side of the tractor. Clamps, includingbolts carried by the carriage, engage the track to hold the backhoe atany set position along the length of the track.

In the backhoe of the present invention, the track consists of a pair ofhorizontally-extending, rearwardly-opening C-shaped slots in thetransverse frame which receives clamping blocks and bolts, the threadedend of each of which projects through the slot and is received in a borein the carriage. Upon tightening a nut on each bolt against thecarriage, the carriage is securely clamped against displacement alongthe track.

The improved clamping mechanism includes blocks within the C-shapedslots which, upon tightening the clamping bolts, laterally expand tospan across the inner walls of the slot and secure the carriage againstloosening and movement as the backhoe is operated.

Among the objects of the present invention is to provide an improvedbackhoe construction in which the carriage clamp does not tend to loosenduring operation; to provide such a construction in which the carriageis firmly clamped without the necessity of tightening auxiliary bolts orwedgers; and generally to improve mechanisms of the type described.

Other objects, and objects relating to details and economies ofconstruction and use will be more apparent from the detailed descriptionto follow.

My invention is clearly defined in the appended claims. In the claims,as well as in the description, parts may at times be identified byspecific names for clarity and convenience, but such nomenclature is tobe understood as having the broadest meaning consistent with the contextand with the concept of my invention as distinguished from the pertinentprior art. The best form in which I have contemplated applying myinvention is illustrated in the accompanying drawings forming a part ofthis specification in which:

FIGURE 1 is an isometric view of a tractor with backhoe and loaderattached, only the rear portion of the tractor and loader being shown.

FIGURE 2 is a side elevation of the backhoe unit, the

boom being broken away and the dipstick and bucket not being shown.Portions of the hydraulic hoses are broken away for convenience ofillustration, and a portion of the frame is broken away to show detailsof interior construction.

FIGURE 3 is an enlarged elevation of the clamping mechanism for clampingthe carriage in any adjusted p0 sition along the frame, portions of theframe being broken away or shown in vertical section and portions of thecarriage being broken away.

FIGURE 4 is a perspective view of the bolts, clamping blocks andassociated parts for clamping the carriage in any adjusted position.

Referring to FIGURE 1, the backhoe of the present invention is adaptedfor mounting on a tractor 11. The backhoe comprises a boom 12, adipstick 14 and a bucket 15 which are articulated and operated in theusual manner. The boom 12 is pivotally mounted for vertical swingingmovement on a swing frame 16, which is supported for horizontal swingingmovement on a rotary cylinder 17 supported by a carriage 19. The boom12, dipstick 14 and bucket 15 are operated in the customary manner byhydraulic cylinders 20*, 21 and 22, respectively. Operation of thesecylinders is controlled by a bank 24 of manually operated hydrauliccontrol valves connected with the cylinders 20', 21 and 22 by hoses 23.

The backhoe 10 is supported on the tractor 11 by a main frame 25 securedto the chassis of the tractor. The main frame 25 extends between therear wheels of the tractor, one wheel 26 being shown and projectssomewhat behind the wheels, terminating in a vertical, relatively flatrear face 27 provided with a pair of vertically-spaced, parallel,horizontal, rearwardly-opening C- shaped slots extending from side toside of the tractor and supporting the carriage 19, as will bedescribed. A pair of stabilizers 30 and 31 are pivotally mounted on thelower portion of the main frame 25 and may be lowered during use of thebackhoe to aid in stabilizing the tractor 11 against overturning and totake the weight off the rear wheels of the tractor.

A rearwardly facing operator seat is mounted on the backhoe main frame25 adjacent the valve bank 24.

Referring now more specifically to FIGURES 2 and 3, the backhoe mainframe 25 preferably is a welded assembly of parts including fourchannels 34, each of the channels extending transversely from side toside of the tractor and being arranged in pairs with facing spacedflanges 35 forming the lips of the C-shaped slots 29. The outer surfaceof the rear flange 35 lies generally in the plane of the rear face 27 ofthe main frame, as indicated in FIGURE 3. The webs 36 of the channels 34extend forwardly from the rear face 27 of the main frame and form theopposite side faces of the C-shaped slots 29. Preferably, a plate 37extending between the webs 36 of each pair of flanges forms the bottomof each C- shaped slot 29 and holds the flanges against spreading due toclamping action against the webs 36, as will be explained.

The carriage 19 is supported on the rear face 27 of the main frame 25and clamped in any adjusted position along the C-shaped slots 29 by theclamping mechanism best shown in FIGURE 4. This clamping mechanismcomprises a first block 39 adapted to be received within each C-shapedslot 29 and having a hole 40 adjacent each end for closely receiving abolt 41. Two bolts 41 project through each C-shaped slot 29, extendbeyond the rear face 27 of the main frame and. are received within bores42 in the carriage 19. Nuts 44 on the bolts 41 serve to clamp thecarriage in any adjusted position along the C-shaped slots, as indicatedin FIGURE 3.

A second block 45 is located within each C-shaped slot 29, the secondblock having a rearwardly tapering hole 46 adjacent each end to receivebolts 41, the blocks 45 preferably having a stepped or offset crosssection to locate the offset portion 47 of the block in the generalplane of the block 39 (see FIG. 3). A bushing 49 is received on eachbolt 41 between the blocks 39 and 45 3 and is provided with a conical ortapering outer periphery 50 coacting with the holes 46 of the block 45.

The arrangement is such that as the nuts 44 are tightened, the blocks 39and 45 will be drawn together, the block 39 carrying the bushings 49into engagement with the block 45 so as to laterally expand the assemblyof blocks 39 and 45, In addition, the rear face 51 of each block 45preferably is provided with converging upper and lower surfacesgenerally matching the taper of the flanges 35 forming the lips of theC-shaped slot. Thus, upon tightening the nuts 44, not only is thecarriage 19 firmly clamped against the rear face 27 of the main frame,but the outer edge portion of the block 39 and the opposite, offsetportion 47 of the block 45 also is pressed outwardly into firmengagement with the opposite side faces of each C-shaped slot so as tolock the above-described clamping assembly against any movement withinthe C- shaped slots and thereby prevent loosening of the clamps andunintended movement of the carriage 19 along the slots. At the sametime, upon loosening nuts 44, the blocks 39 and 45 will separateslightly, thus loosening the clamping means and permitting readyadjustment of the carriage along the slots. The plate 37 extendingbetween the webs 36 of each pair of channels prevents spreading of thechannels by the outwardly-pressed blocks 39 and 45.

I claim:

1. In an adjustable offset backhoe in which a backhoe boom is supportedon a tractor by a carriage slidable along a track carried by a frame onthe rear of the tractor, the improvement comprising: the track beingformed by a frame having members defining two spaced, parallelrearwardly-opening, C-shaped slots extending across the rear of thetractor, bolts extending from the slots and 4 received within holes inthe carriage and adapted to be tightened to draw the carriage againstthe frame, a block within each slot and engaged by at least one of thebolts, the block having two complementary portions adapted to be cammedlaterally outwardly upon tightening of the bolt so as to cause the blockto laterally expand and wedge between opposite walls of the C-shapedslot and to clamp the block against the inner face of the margins of theslot.

2. In an adjustable offset backhoe as claimed in claim 1, the membersdefining each of the slots comprising two parallel, transverselyextending channels having facing, spaced flanges defining the margins ofthe slot.

3. In an adjustable offset backhoe as claimed in claim 2, themid-portion of the flanges of the channels defining each slot beingjoined by a plate forming the bottom of the slot and aiding inpreventing spreading of the channels due to outward force of the blocks.

4. In an adjustable offset backhoe as claimed in claim 1, one of theblocks being laterally fixed relative to the bolt and the other blockhaving a tapering hole receiving the bolt, and a cooperating taperingmember carried into engagement with said tapering hole by said one blockto center the hole of said other block about said bolt, centeringmovement of said other block serving to press the lateral edges of theblocks outwardly into firm engagement with the opposite side faces ofthe slot.

References Cited UNITED STATES PATENTS HUGO O. SCHULZ, Primary Examiner.

